EP2870406A1

EP2870406A1 - Solid state lighting luminaire with modular refractors

Info

Publication number: EP2870406A1
Application number: EP13816884.4A
Authority: EP
Inventors: Robert Fugerer; Rick Kauffman; Donald Vandersluis
Original assignee: Evolucia Lighting Inc
Current assignee: Evolucia Lighting Inc
Priority date: 2012-07-09
Filing date: 2013-07-09
Publication date: 2015-05-13
Also published as: EP2870406A4; CN104822984A; WO2014011670A1

Abstract

Solid State Lighting (SSL) luminaires, and methods for constructing the same, are provided, with the SSLs having enhanced efficacy through reduction of the number of lens surfaces through which light must pass while still providing the necessary protection against the environment. Modular refractors are provided having optic components that may be coupled with lighting modules. The modular refractors may provide environmental protection to lighting components housed within the refractor, and a separate external protective lens may not be required. One or more lenses of one or more of the modular refractors may include materials of at least two different refractive indices that are co-molded together.

Description

SOLID STATE LIGHTING LUMINAIRE WITH MODULAR REFRACTORS

BACKROUND

[0001] Solid-State Lighting (SSL), based on Light Emitting Diodes (LEDs), is increasing in market penetration versus traditional lighting technologies. Luminaires based on LEDs have significant advantages over traditional lighting technologies such as longer lifetime, mechanical ruggedness, greater efficiency, and are free of dangerous pollutants such as mercury.

[0002] While conventional luminaires typically require only a singular light source, such as a metal halide bulb, SSL luminaires generally perform optimally using a plurality of LEDs. While traditional light sources generally emit light nearly omni-directionally, high-power LEDs generally emit light in a Lambertian pattern. If an LED is to be optimally efficient as a light source, its aiming and beam spread should be controlled individually or in very small groups. Typically, effective aiming can be implemented by mounting the LEDs to a printed circuit board (PCB) which is in turn mounted to an aiming platform which orients each LED or small group of LEDs in the required direction. This platform also provides heat sinking so as to cool the LEDs and allow them to maintain proper operating temperature. Controlling beam spread is accomplished by either using a total internal reflection (TIR) lens that collimates the output of each LED or a compound parabolic reflector or similar to direct the light as needed. Further control is accomplished via spreading lenses that may either be incorporated into the final surface of the collimating lens or added as a secondary element to that lens. For most luminaires, particularly outdoor luminaires, protection against the elements requires another, external protective lens. With each additional lens come two additional surfaces and the material in between. Since each lens surface has some amount of reflectivity, the amount of light transmitted through said lens decreases, reducing overall efficacy of the luminaire.

SUMMARY

[0003] The present disclosure recognizes that having multiple surfaces through which light must be transmitted may degrade overall performance of a luminaire. Provided in the present disclosure are luminaires that have increased efficacy through a decrease in the number of surfaces through which the light passes, and/or a decrease the amount of material through which the light passes.

[0004] Various aspects of the disclosure describe several novel SSL luminaires with greater efficacy through reduced numbers of lens surfaces through which the light must pass while still providing the necessary protection against the environment. This provides for both greater efficacy and more cost-effective production of SSL luminaires.

[0005] Therefore, one option for increasing efficacy in a given luminaire is to reduce the number of surfaces through which the generated light must pass. Various aspects of the present disclosure provide systems, methods, and apparatuses to reduce the number of surfaces through which light must pass by incorporating spreading lenses and the protective external lens into a single apparatus, a modular refractor. An additional gain in efficacy may be realized by using compound-parabolic reflectors to collimate the light produced by the LEDs, rather than a TIR-type lens, thereby minimizing not only the number of surfaces that the light engages but also the volume of lens material through which it passes.

[0006] In one aspect, a solid state lighting apparatus is provided. The apparatus generally includes a housing having a number of different mounting surfaces, a number of light modules coupled with the various mounting surfaces, and a number of modular refractors, each modular refractor coupled with a corresponding light module and including one or more lenses configured to control of the spread of light generated from one or more light emitting diode (LED) lighting elements coupled with the associated light module. Each modular refractor may provide environmental isolation from at least some of the components of the associated light module. In some embodiments, the number of mounting surfaces may have several different mounting angles relative to a surface to be illuminated by the apparatus. In some further embodiments, the apparatus does not include a separate external protective lens, thus reducing the number of surfaces light must traverse and enhancing the efficacy of the apparatus.

[0007] In some embodiments, at least a subset of the light modules include two or more LEDs coupled with a printed circuit board (PCB), with the PCB mounted to an associated mounting surface. In some embodiments, one or more of the mounting surfaces may include a heat sink configured to transfer heat away from the associated LEDs.

[0008] The modular refractor, in some examples, may include one or more of a total internal reflection (TIR) lens or a compound parabolic reflector. One or more of the lenses may also include spreading lens incorporated into an external lens surface or coupled with the external lens surface as a secondary element to the lens. One or more lenses of each modular refractor, according to some embodiments, are integrated with a modular refractor housing and formed on either an inside surface or outside surface of the housing. In further embodiments, one or more lenses of some or all of the modular refractors include materials of at least two different refractive indices that are co-molded together. In still further embodiments, one or more lenses of one or more of the modular refractors may include a gradient index (GRIN) lens molded into the modular refractor.

[0009] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the spirit and scope of the appended claims. Features which are believed to be characteristic of the concepts disclosed herein, both as to their

organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purpose of illustration and description only, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A further understanding of the nature and advantages of the present disclosure may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components.

[0011] FIG. 1 is a front perspective view of a modular refractor according to various

embodiments;

[0012] FIG. 2 is a is a rear perspective view of a modular refractor according to various embodiments;

[0013] FIG. 3 is a side elevation view of a modular refractor according to various embodiments; [0014] FIG. 4 is top plan view of a modular refractor according to various embodiments; [0015] FIG. 4A is a cross section view along section A-A of FIG. 4; [0016] FIG. 5 is a detail view of a portion of FIG. 4A;

[0017] FIG. 6 is a front perspective view of a light module according to various embodiments;

[0018] FIG. 7 is a top plan view of a light module according to various embodiments;

[0019] FIG. 8 is a front perspective view of another modular refractor according to various embodiments;

[0020] FIG. 9 is a bottom perspective view of a street light according to various embodiments;

[0021] FIG. 10 is another perspective view of a street light according to various embodiments; and

[0022] FIG. 11 illustrates exemplary mounting surfaces for a light module and modular refractor according to various embodiments.

DETAILED DESCRIPTION

[0023] The following description provides examples, and is not limiting of the scope, applicability, or configuration set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the spirit and scope of the disclosure. Various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in other embodiments.

[0024] SSL luminaires are being installed throughout the USA and around the globe. LED- based lighting is replacing traditional light sources such as incandescent, metal halide and sodium vapor lamps in ever increasing numbers. Solid State Lighting saves energy, reduces operational expenses and minimizes maintenance and its associated costs. The ruggedness, longevity and efficiency (among other qualities) of LEDs have continued to increase the number of applications and the market share of SSL luminaires. [0025] Commonly, many SSL luminaires are designed with their LEDs arrayed in simple linear patterns, which achieves only a poor approximation of the light pattern required. This may result in poor uniformity or there may light spread outside the desired area. This reduces the effective use of the available light. Precise aiming of individual light emitting diodes or of small groups of light emitting diodes provides much greater control of the light pattern and more efficiently utilizes the light produced. Precise aiming may be accomplished in a variety of ways including aiming platforms that are cast, molded, formed, bent or otherwise structured to provide the requisite number and position of aiming points needed to achieve the required pattern of light on the ground.

[0026] Typically, the LEDs of SSL luminaires have collimating lenses or compound-parabolic reflectors, spreading lenses and an external protective lens or refractor. Efficacy is a measure of how efficiently a given luminaire produces light vs. the amount of electrical power consumed. Since any practical material used for lenses exhibits some loss at each lens surface, the greater number of surfaces through which the light must pass, the greater the loss of light and therefore the lower the efficacy.

[0027] In one exemplary embodiment of the disclosure, a modular refractor 1 , as shown in Figure 1 , has molded, cast or otherwise formed spreading lens areas 2 that provide the necessary control of the spread of light generated from one or more LED lighting elements located within the refractor housing. These areas may be formed on either the inside surface, the outside surface as shown in this exemplary embodiment, both surfaces or formed internally using co-molding of materials of at least two different refractive indices or formed using a gradient index (GRIN) lens molded into the modular refractor 1. While this exemplary embodiment shows a plurality of these spreading lens areas, there may embodiments wherein the number of such spreading elements differs from this exemplary embodiment including such an instance wherein there is only a single such element. The mounting frame 3 provides the first level of protection against the external environment along with a gasket 4, shown in Fig. 2. The mounting frame 3 as depicted here is shown for illustrative purposes and may in practice take various shapes as needed to fit the requirements of a particular luminaire.

[0028] The mounting ears or ledges 5 in Fig. 2 are part of the modular refractor 1 and provide area for sealing against the gasket 4 and also for positioning said modular refractor on its mounting platform. A metal-clad printed circuit board (PCB) 6 provides mounting for LEDs along with the circuitry which connects them. The metal-clad PCB 6 is used in the exemplary embodiment in order to provide a thermally conductive path from the bases of the LEDs to the mounting platform that is allows sufficient heat removal for proper operation and longevity of the LEDs. Such a PCB also insulates the operational circuitry powering the LEDs from the mounting platform. An electrical connector 7 which is shown in figures 2 and 3 provides a means for connecting the LEDs inside the module to an external power source. The mounting hardware 8 may be any of several various fasteners familiar to those skilled in the art and, in this exemplary embodiment, holds both the internal collimating elements to the PCB 6 and also is used to secure the PCB 6 to the mounting platform.

[0029] The LEDs 9 are shown in FIG. 4 and in the cross section view of Fig. 4A and are positioned within internal collimating elements 10 which in this exemplary embodiment are compound parabolic reflectors which collect and collimate the light generated by the LEDs. In other embodiments, the collimating elements may be cast or molded lenses which may be of the total internal reflection type. These lenses may be independent from the modular refractor or may be part of the same mold or casting, thereby reducing even further the number of surfaces through which the light must pass. The spreading lens area 2 then disperses or spreads the light to the extent needed to meet the requirements of this module for a given luminaire design.

[0030] The inner gasket 11 shown in Figures 4 and 5 seals the modular refractor 1 to the PCB 6 providing an additional level of protection against the external environment and thereby creating an individually sealed module. The inside of this module is shown in Figures 6 and 7. Also shown in these figures are internal electrical connections 12 which are soldered directly to the metal-clad PCB and provide a means to connect the LEDs mounted on the PCB 6 to be powered from the external connector 7. Not shown for clarity are the electrical wires connecting said connectors. In other possible embodiments, another implementation of an external connector 7 may itself be soldered directly to the PCB 6.

[0031] The mounting ears or ledges 5 of the modular refractor 1 are shown without the mounting plate in Fig. 8. In other embodiments, these may vary in relative dimension from that shown in this exemplary embodiment. Other embodiments of the modular refractor 1 may also differ from the rectangular form shown in this exemplary embodiment. These alternative forms may be square, circular, hexagonal, triangular or whatever other shape may be needed to fit the requirements of a given luminaire 's design. It is given that the components internal to the modular refractor would be rearranged, altered or otherwise constructed so as to fit with the alternative shape of the modular refractor. [0032] In the exemplary embodiment shown in Figures 9 and 10, the modular refractor assemblies 13 are mounted to an aiming platform 14 which orients each module so as to achieve the required pattern of light on the ground and also provides a thermally conductive path to the housing 15 which provides structural support, thermal conductivity and thermal dissipation. The housing 15 may be cast, molded, machined, sintered or formed in some other fashion and of a material that provides both the necessary mechanical strength and also the required thermal conductivity, typically aluminum. The housing 15 is then covered by an external skin 16 that provides both the desired aesthetic as well as additional protection from the environment.

[0033] The areas 18 around and behind the modular refractor assemblies 13 are covered and protected from the environment by a mounting frame 17 that may be sectional as shown in the exemplary embodiment or may be a single piece or a plurality of individual pieces, depending upon the requirements of a given luminaire's design. The sectional mounting frame 17 was conceptually represented in earlier figures by a simplified mounting frame 3 and is backed by a gasket or gaskets functionally similar to the gasket 4 shown in earlier figures. Figure 11 depicts said sectional mounting frame 17 independent of the rest of the luminaire assembly. Openings 19 in the frame are sized appropriately to accommodate the modular refractor assemblies.

[0034] Not shown in this exemplary embodiment are the connectors mounted on the aiming platform 14 which would mate to the connectors 7 on the modular refractor assemblies 13. These mating connectors would be positioned so as to allow the modular refractor assemblies 13 to plug into the aiming platform 14 to establish the requisite electrical connections to power the LEDs. The connectors mounted on the aiming platform 14 would be wired together in the appropriate configuration to optimize power utilization. This wiring would be run in the area 18 behind the modular refractor assemblies 13 and would be protected from the environment by the mounting frame 17, as will be readily understood by one of skill in the art.

[0035] One alternative embodiment not shown in the drawings would be to have wiring run through a hole in the PCB 6 rather than use a connector as depicted in the drawing figures. This would require the wiring to be directly connected to the electrical connections 12 and that the spaces left in the hole after the wiring was run be sealed with a compound such as room- temperature vulcanizing (RTV) silicone, commonly used to seal against ingress of water and other substances. [0036] Also not shown in the drawings, for sake of clarity in the illustrations, are various fasteners and the holes needed to receive them in the pertinent components. Such items and the use of same will be readily understood by one of skill in the art.

[0037] The detailed description set forth above in connection with the appended drawings describes exemplary embodiments and does not represent the only embodiments that may be implemented or that are within the scope of the claims. The term "exemplary" when used in this description means "serving as an example, instance, or illustration," and not "preferred" or

"advantageous over other embodiments." The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described embodiments.

[0038] The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Throughout this disclosure the term "example" or "exemplary" indicates an example or instance and does not imply or require any preference for the noted example. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

What is claimed is:

1. A solid state lighting apparatus, comprising:

a housing comprising a plurality of mounting surfaces;

a plurality of light modules coupled with the plurality of mounting surfaces; and

a plurality of modular refractors, each modular refractor coupled with a corresponding light module and comprising one or more lenses configured to control of the spread of light generated from one or more light emitting diode (LED) lighting elements coupled with the associated light module, and each modular refractor providing environmental isolation from at least some of the components of the associated light module.

2. The apparatus of claim 1, wherein the plurality of mounting surfaces have a plurality of different mounting angles relative to a surface to be illuminated by the apparatus.

3. The apparatus of claim 1, wherein the apparatus does not include a separate external protective lens.

4. The apparatus of claim 1, wherein at least a subset of the plurality of light modules comprises two or more LEDs coupled with a printed circuit board (PCB), and wherein the PCB is mounted to an associated mounting surface.

5. The apparatus of claim 4, wherein at least a subset of the mounting surfaces comprise a heat sink configured to transfer heat away from the associated LEDs.

6. The apparatus of claim 1, wherein one or more of the lenses comprise a total internal reflection (TIR) lens or a compound parabolic reflector.

7. The apparatus of claim 6, wherein one or more of the lenses further comprise a spreading lens incorporated into an external lens surface or coupled with the external lens surface as a secondary element to the lens.

8. The apparatus of claim 1, wherein the one or more lenses of each modular refractor is integrated with a modular refractor housing and formed on either an inside surface or outside surface of the housing.

9. The apparatus of claim 1, wherein the one or more lenses of one or more of the modular refractors comprise materials of at least two different refractive indices that are co-molded together.

10. The apparatus of claim 1, wherein the one or more lenses of one or more of the modular refractors comprise a gradient index (GRIN) lens molded into the modular refractor.